1. Technical Field
Aspects of the present invention generally relate to an image processing apparatus to perform recording by using a plurality of color materials and a control method for the image processing apparatus.
2. Description of the Related Art
In recording by an inkjet recording apparatus, color development and gloss varies according to the order of impacts of color materials. Therefore, it is known that color unevenness and/or gloss unevenness occur when the order of impacts of the color materials varies for each image region. Specifically, in a case where pigment inks are used as the color materials, the influence on a recording medium becomes remarkable depending on the order of impacts of the color materials.
Generally, a recording head of the inkjet recording apparatus is equipped with a plurality of recording elements (i.e., nozzles) for each color material. However, malfunction may sometimes occur in some of the recording elements. An example of the malfunction includes defective discharge of the color material. When the defective discharge of the color material occurs, the color material is not discharged to a position to be originally recorded on the recording medium, resulting in occurrence of a visually unpleasant stripe unevenness in an image formed on the recording medium.
Therefore, in a multipass recording method, such a technique that the defectively discharging nozzle due to the malfunction (hereinbelow referred to as “defective nozzle”) is complemented by the other normal nozzles is discussed in, for example, Japanese Patent Application Laid-Open No. 2000-94662. According to the method discussed in Japanese Patent Application Laid-Open No. 2000-94662, even when a defective nozzle arises, the color material still can be discharged to the position on the recording medium to be originally recorded.
However, in the method discussed in Japanese Patent Application Laid-Open Publication No. 2000-94662, since a print pattern is changed for each scan, the order of impacts of the color materials in a main scanning line corresponding to the position to be originally recorded by the defective nozzle may be changed with the other main scanning line. As a result, the color unevenness and/or the gloss unevenness may occur on the image to be formed.